1. Field of the Invention
Cytomegalovirus is a double stranded DNA virus, approximately 240,000 nucleotides in length, belonging to the herpesvirus group. Human cytomegalovirus ("hCMV") has become increasingly involved in a wide of variety of diseased states. In the United States, hCMV infects in utero about 1% of all newborns and is currently the most common infectious cause of birth defects. hCMV infections have a major impact on immunocompromised patients. There is abundant data to indicate that hCMV is considerably more virulent than other viral agents in patients undergoing immunosuppression. Both animal and human studies suggest that CMV is latent in white blood cells. Many herpesviruses appear to have oncogenic properties.
At present, there is no effective CMV vaccine and no antiviral therapy is available. Definitive diagnosis of CMV infections is made by growing the virus in tissue culture, which may take as long as six weeks. In many situations, the early diagnosis of hCMV could be important in the prevention of a seriously malformed neonate, where the mother is compromised by CMV. A simple, rapid and accurate screening technique is essential for detecting CMV during pregnancy, with immunosuppressed patients, and in the detection of blood donors capable of transmitting hCMV.
2. Description of the Prior Art
Tamashiro et al., J. Virology (1982) 42:547-557 describe a construction of a cloned library of EcoRI fragments from the hCMV genome. Spector et al., Ibid. (1982) 42:558-582 describe restriction cleavage maps for hCMV DNA strain AD169. See also references cited therein. Chou and Merigan, Abstracts of the 22nd Interscience Conference on Antimicrobial Agents and Chemotherapy 4-6 Oct., 1982, Miami Beach, Fla., p. 96, item 180, describe the use of a CMV fragment (O) to detect CMV in urine specimens.